Bad news is if you have root access and you want to keep it, you should probably wait (unless you want to got through the rooting process again) until a ‘fixed’ version of 1.5 comes out.
If you don’t care about root access you can update by:
- Download the signed-kila-ota-148830.de6a94ca.zip file,
- Rename it to ‘update.zip’ (note: by default, Windows hides file extensions- so be sure you are not naming it ‘update.zip.zip’ by un-hiding extensions if this doesn’t work)
- Copy the ‘update.zip’ file to the root directory of your MicroSD card
- Power off your G1
- Power on your G1 while holding down the ‘home’ button
- When the warning triangle comes up, press alt+L on the keyboard
- Next hit atl+S on the keyboard
- It will prompt you to hit home+back to reboot a few times.
- After this, you should be to 1.5 firmware (and you will need to re-setup your phone)